Coating removal device



June 20, 1967 5. J. GARTNER 3,326,224

COATING REMOVAL DEVICE Filed Sept. 29, 1965 4 Sheetsheet l INVENTOR. E 55mm. J GART/VER ATTORNLY June 20, 1967 5, GARTNER 3,326,224

COATING REMOVAL DEVICE Filed Sept. 29, 1965 4 Sheets-Sheet 2 M3INVENTOR.

5 STANLEY J G/IRTNER 1 B Y wi M ATTORNEY June 20, 1967 5. J. GARTNER3,326,224

COATING REMOVAL DEVICE Filed Sept. 29, 1965 4 Sheets-Sheet Z l INVENTOR.

.57'HNLEY J G/mr/vm E5 7 BY ,aMzM

June 20, 1967 s. J. GARTNER COATING REMOVAL DEVICE 4 Sheets-Sheet 4Filed Sept. 29, 1965 INVENTOR. STANLEY J. GARTNER ATTORNEY United StatesPatent 3,326,224 COATING REMGVAL DEVICE Stanley Jacob Gartner, Emporium,lPa., assignor to Sylvania Electric Products Inc., a corporation ofDelaware Filed Sept. 29, 1965, Ser. No. 491,131 4 Claims. (Cl. 134--58)This invention relates to the manufacturing of cathode ray tubes andmore particularly to a coating removal device for achieving improvedlacquering and aluminizing of the screened panel thereof.

It is conventional practice in the art of manufacturing color televisioncathode ray tubes, to apply a thin film or coating of aluminum to theback of the cathodoluminescent phosphor screen, that being the screensurface normally oriented toward the electron gun in the tube and awayfrom the viewer. This aluminum coating provides a mirror-like finishwhich reflects, toward the viewer, a portion of the light from thescreen which would otherwis be lost within the tube. It has been foundthat tubes so treated exhibit improved brightness and contrast indisplay presentation that is not evidence in non-aluminized tubes.

In color cathode ray tube fabrication, a multi-phosphor patterned screenis usually applied on the inner surface of the substantially cup-shapedtube face panel in a manner to be suitably viewed therethrough. Theformed screen is thence processed before the face panel is hermeticallyjoined to the funnel or envelope portion of the tube. The pluralcathodoluminescent phosphors, per se, are suitably disposed asmultitudinous dots or discrete stripes in accordance with the severalestablished procedures well known to the art. Prior to the applicationof the aluminized mirror coating, the multi-phosphor screen is precoatedor overlaid with a thin film of lacquer to provide a suitable surfaceupon which to form the mirror. In addition, the lacquer serves as atemporary barrier to prevent the aluminum from penetrating and poisoningthe phosphor crystals, thereby reducing or destroying the luminescentqualities thereof, during the aluminizing procedure. This lacquer filmis subsequently removed by baking whereupon the reflective aluminumremains supported directly by the phosphor screen.

The deposition of the lacquer film, whether it be by the spray or slurrytechniques, usually covers the whole of the interior of the face panel,coating not only the screen portion but also the peripheral panel skirtor sidewall area as well.

The aluminum coating is conventionally applied by a vaporizationtechnique and usually covers the whole of the interior of the screenedpanel including the sidewall area. Since the lacquer is removed from thescreen area by baking subsequent to aluminizing, it is important toremove all traces of lacquer from the sidewall area, peripheral to thescreen, prior to aluminizing as any residual lacquer underlaying thealuminium or the substantially smooth sidewall area prevents adherenceof the aluminum to glass, and results in localized blistering of thealuminum coating when said residual lacquer is volatilized fromtherebetween during the aforementioned subsequent panel bake-out. It isimportant to have tight adherence of the aluminum coating to the panelsidewall not only to prevent blisters but also to insure electricalcontinuity of the anode coating covering the interior surface of thetube evelope; of which, the aluminum on the panel sidewall is anintegral part.

Upon drying of the disposed lacquer, prior to deposition of thealuminizing film thereover, removal of the extraneous lacquer from theinner surface of the panel sidewall is a substantially manual operation.A lint-free cloth,

moistened with a suitable solvent is utilized to expedite softening andremoval of the lacquer film from the panel skirt. This operationrequires manual dexterity, especially in the areas surrounding theseveral metallic buttons that are embedded in the sidewall of the panel,as it is desired to remove all of the extraneous lacquer up tosubstantially the edge of the screen. It has been found that theundesired lacquer can be manually removed with a solvent moistened clothby exercising proper care and diligence when the film is substantiallydry. Attempting to remove the wet lacquer adjacent the screen, with asolvent moistened cloth, is an extremely delicate time consumingoperation as the wet lacquer tends to smear. Therefore, removal of thedried film is the better method, but it is not entirely withoutcomplications as the wiping action tends to produce a somewhat roughenededge, and, in addition, there is the aforementioned difiiculty ofentirely removing all of the dried lacquer from the skirt area.Unfortunately, inadequate removal of the extraneous lacquer from theskirt area is not evidence until after consummation of the subsequentaluminizing and lacquer bake-out processing steps. It is then that thetell-tale blisters make their appearance to indicate aluminizing ofinferior quality along with a resultant increase in the scrap level ofthe manufacturing process. Even though the blisters may be small and notruptured, they still are undesirable as they provide a possible sourceof loose metallic particles within the tube. Therefore, it is highlydesirable to prevent blistering and at the same time insure electricalcontinuity by removing all traces of the lacquer film from that portionof the face panel where it is not desired.

Accordingly, an object of the invention is to reduce the aforementioneddisadvantages and to provide improved aluminizing for color cathode raytube fabrication.

Another object is to provide an apparatus for discretely removing anextraneous portion of the lacquer film beyond the screen area of acathode ray tube face panel to promote the formation of an unblemishedfilm of aluminium over the whole of the interior of the screened panel.

A further object is to provide a lacquer coating removal device forremoving the lacquer coating from the sidewall portion of the screenedface panel.

An additional object is to improve the quality of the aluminized colorcathode ray tube product and to provide improved efficiency in tubemanufacturing.

The foregoing objects are achieved in one aspect of the invention by theprovision of a lacquer removal apparatus whereby the applied lacquer,which forms an underlay over the screen for the subsequent aluminumcoating, is removed, while still in the liquid stage, from the skirt orsidewall portion of the panel adjacent the screen area. This isaccomplished by utilizing apparatus means to support and rotate thecoated panel in an inverted position while at least one tracking means,with an attached nozzle thereon is oriented to perimetrically follow theinner sidewall surface. The nozzle is maintained in substantiallyequidistant relationship with the sidewall portion, and a substantiallyconstant pressure stream of water issuing from the nozzle forms animpingmen-t pattern on the panel sidewall to flush away thewater-insoluble lacquer material from the sidewall portion before filmformation thereof materializes.

For a better understanding of the present invention, together with otherand further objects, advantages, and capabilities thereof, reference ismade to the following specification and appended claims in connectionwith the accompanying drawings in which:

FIGURE 1 is a partial cross-sectional "view of a color cathode ray tubeface panel showing the cathodoluminescent screen with the lacquercoating covering the whole of the interior surface of the panel;

FIGURE 2 is another partial cross-sectional view of the same panelshowing means for discretely removing the lacquer coating from thesidewall portion of the panel;

FIGURE 3 is still another partial cross-sectional view showing the panelwith the lacquer removed from the sidewall portion of the panel;

FIGURE 4 is a top plan view showing details of the apparatus utilizedfor removing the lacquer coating from the sidewall portion of the facepanel;

FIGURE 5 is a partially detailed elevational view taken along the line55 of FIGURE 4, with portions omitted to provide clarity, illustratingcertain important features of the lacquer coating removal device;

FIGURE 6 is a partially sectioned elevational enlargement of theapparatus taken along the line 6-6 of FIG- URE 4 detailing panel supportmeans utilized prior to initiating lacquer coating removal;

FIGURE '7 is a plan view showing horizontal orientation of the paneltracking means of the apparatus;

FIGURE 8 is an enlarged exploded perspective showing features of thepanel tracking means; and

FIGURE 9 is a top plan view showing adaptations for accommodating arectangular cathode ray tube face panel in the lacquer coating removalapparatus.

In referring to the drawings, FIGURES 1, 2, and 3 show cross-sectionalelevations of a cathode ray tube face panel 11 before attachment to theenvelope funnel portion. Suitably embedded within the wall of skirtportion 15, and spaced therearound, are a plurality of metallic buttons17, one of which is shown. The function of these buttons is to properlyorient and support a foraminous shadow mask or grid, not shown, which isutilized for both screen formation and subsequent tube operation. Thepanel which may be round, elliptical, or rectangular in shape, has asubstantially transparent viewing portion 13 and a sidewall or skirtportion 15 perimetrical thereto. On the inner surface of the panel apatterned cathodoluminescent screen 19, comprising a repetitiveplurality of color-emitting phosphors, is suitably disposed inaccordance with one of the known techniques of the art.

After the forming of the screen, the whole of the interior of the facepanel 11 is rinsed with an aqueous wetting solution, not shown,containing a quantity of a selected water soluble organic solvent whichlowers the surface tension of the water. This provides uniform wettingof the panel and enables the aqueous solution to more closely follow thehorizontal contour of the phosphor screen. When the lacquer coating isapplied to the interior of the panel, the aqueous wetting film, beingcontiguous upon the topography of the screen, forms a thin continuousbarrier to prevent lacquer penetration of the phosphor materialscomprising the screen and thereby facilitates the deposition of auniform lacquer coating 21 thereover.

A lacquer material formulation suitable for this usage has been found tocomprise a solution of acrylic resin solids dissolved in at least oneorganic solvent selected from the group consisting essentially oftoluene and xylene with the resin solids therein ranging substantiallyfrom 4.6 to 5.0 percent by weight. A suitable plasticizer, such asdibutyl phthalate, is added thereto in an amount less than one percentbased on the weight of the resin solids. The resultant lacquer solutionhas a viscosity substantially within the range of 3.8 to 4.4 centistokesat 25 degrees Centigrade. When toluene alone is used as the solvent,lacquer set-up progresses in approximately 45 seconds (at approximately25 degrees centigrade) to a film formation state. Thus, if theextraneous lacquer coating, disposed on the panel sidewall, is to beremoved by water flushing, such operation must be initiated withinapproximately 35 seconds of lacquer application. It has been found that,if desired, the time of lacquer film formation can be retarded by addingxylene to the lacquer formulation with the toluene content beingdecreased accordingly.

The lacquer material is applied as a coating over the whole of theinterior of the panel in accordance with one of the procedures known tothe art such as by slurrying or spraying. From a manufacturingconsideration, it is desired that the extraneous lacquer coating beremoved from the panel sidewall immediatly following lacquer coatingapplication.

With reference to FIGURE 2, there is shown the apparatus forexpeditiously removing the lacquer coating from the panel sidewall inaccordance with the invention. The freshly lacquered panel 11 to besubjected to the discrete lacquer removal operation, is horizontallyoriented and supported with the open face thereof in a downward positionby suitable means not shown in FIGURE 2 but subsequently illustrated inFIGURES 4 and 6 and fully described later in this specification. Aplurality of liquid-issuing nozzles 23, one of which is shown, areoriented in a predetermined horizontal plane in a manner to maintain asubstantially equidistant relationship with the skirt or sidewallportion 15 of the panel 11. Thus, when relative rotation 25 is providedbetween the panel sidewall 15 and the nozzle 23, the stream of liquid 27issuing from the nozzle impinges upon the sidewall with desiredconstancy in a circumferential or perimetrical sweeping motion. In thisinstance the stream of liquid 27 is water, free from contaminatinginclusions, although the invention is not intended to be limited to suchas other compatible solvents may also be utilized.

With further reference to FIGURES 2 and 7, the noz- Zle 23 has alongitudinal axis 29 extended therethrough and sequentially maintainedin a pivoted manner to effect substantially right angle relationshipwith a progressive line 33 tangential to the inner perimeter of thesidewall 15. Thus, during the relative rotational movement of the panelsidewall and the nozzle, there is maintained therebetween both asubstantially constant distance and a substantially consistent angularorientation. These factors coupled with a water supply of constantpressure that is free of cavitations and gaseous inclusions provide astream of water 27 that is discretely nozzle formed and directed towardthe inner portion of the panel sidewall 15. The pressure of the streamof water is predetermined to effect a constant substantially bulbousterminal formation of water 37 upon impingement with the sidewall. Thisterminal formation of water has a substantially constant areaconfiguration in keeping with the inner con tour of the panel perimeterwhether it be substantially straight or arcuate, to provide asubstantially consistent pattern of impingement thereon and effect adiscretely formed peripheral trimming edge of water having a verticalapex 39 oriented to substantially follow the border 41 of said lacquercoated screen.

When the perimetric contour of the panel is other than arcuate, as forexample, a panel of substantially rectangular shape 43 withsubstantially arcuately formed corners 45, as illustrated in FIGURE 9,it is important that the pattern of water impingement and the trimmingedge thereof exhibit uniformity regardless of the differentialperimetric contour to prevent the trimming water from climbing thecorners of the panel. This uniformity of the liquid trimming pattern isachieved by predetermining the area of water impingement according tothe most acute curvature of the perimeter in conjunction with the paneltracking means 49 fully described later in this specification. Whateverthe size of the water trimming configuration, the volume of the streamof water is sufiicient to completely flush the extraneous lacquercoating from the panel sidewall before the inception of lacquer filmformation. Thus, as shown in FIGURE 3, the cathode ray tube face panel11 is ready for aluminizing, wherein the cathodoluminescent screenportion is covered with a film of lacquer 21 from which the extralacquer beyond the perimeter thereof has been water trimmed and flushremoved to provide a lacquer-free sidewall surface.

In FIGURES 4, 5, and 6 there is shown mechanical means, in the form ofapparatus 48, which expeditiously accomplishes the desired removal ofthe extraneous lacquer from the panel sidewall.

In part, this lacquer removal apparatus 48 comprises a panelaccommodation stage 51, which is circular in shape with a large centralopening 53 therein. This stage is horizontally positioned and adequatelysupported around its peripheral region between vertically oriented pairsof stage rollers 55 contacting the upper and lower surfaces thereof. Atleast three pairs of these rollers are utilized in substantiallyequispatial relationship therearound, each pair being located on asuitable bracket 57 and affixed to the top portion 59 of a horizontalbase platform 61. The lateral placement of the stage is achieved andmaintained by employing at least three spaced apart confining rollers 63positioned to make circumferential contact with the circular stage.These confining rollers are mounted in a horizontal rotatable manneratop vertical holders 65 also oriented on the top of the base platform61.

The periphery 50 of the circular stage 51 is formed to cooperate with anassociated drive or motion imparting means 67. As shown, the peripheryis substantially channel-shaped to receive linear motion transmissionfrom a belt or chain-type linkage 69 which imparts desired rotation tothe stage from a power transfer medium, such as a drive gear or pulley71, for a predetermined period of time to be later explained.

The aforementioned central opening 53 in the panel accommodation stage51 is diametrically larger than the largest dimension of the cathode raytube face panel 11 to be positioned therein. With particular referenceto FIGURES 4 and 6, the lacquer coated face panel 11 is oriented openface down within the above-mentioned central opening 53. It istemporarily held therein in proper horizontal placement by the paneledge 18 resting on the forward portions 77 of at least threespaced-apart panel rests 79. These, being pivoted means formed forvertical movement, are afiixed to the top portion 59 of the baseplatform 61 and extended in a plane substantially parallel therewithtoward the panel accommodation stage 51 thereabove. The forward portions77 are substantially covered with plastic sleeves, as of polyethylenematerial, to provide resilient cushioning for the edge of the panel.

As partially phantomed in FIGURE 6, the fulcrum or pivot 81 permits theforward portion 77 of the panel rest 79 to subsequently drop, at apredetermined time when the panel is otherwise retained by retentionmeans to be described, to a slightly lower position in accordance withprogrammed actuation accorded to the rear portion 83 of the panel rest.An adjustable stop 85 in conjunction with a vertical resilient means 87,such as a helical spring, and a vertical pressure means 89, in the formof an air cylinder having a plunger 91 of restricted stroke, impartspredetermined vertical movement to the forward portion 77, the sequenceof which will be later explained.

With the panel vertically pre-oriented on the panel rests 79, theretention of its horizontal position is facilitated by at least threepanel retainers of two types 93 and 95, spaced apart to make externaltri-point peripheral contact'with the external sidewall portion of thepanel. Each of the two retainers 93, with the respective body portions97 affixed to the panel accommodation stage 51, has a panel contact pad99 of substantially non-resilient plastic material formed and placed tofit the panel external periphery. The third panel retainer 95, whichcompletes the triangulated retention arrangement, is likewise affixed tothe accommodation stage. This retainer is manually operated by lever 101and has a resilient contact pad 103 as of rubber or compressibleplastic. When predetermined pressure is applied by mechanical linkagefrom lever 101, the panel 11 is securely positioned in an undistortedmanner by the three retainers. Thus, the panel and the accommodationstage are oriented with a vertical axis 104 common to both.

With the panel properly positioned and retained relative to theaccommodation stage by the panel retainers 93 and 95, the panel rests 79are dropped free from the edge of the panel to positions in a commonplane therebeneath, and rotary movement is imparted to the stage bydrive means 67. Coating removal means 105, quiescently positioned to bewithin the confines of the inverted panel on a plane substantiallyparallel with the top of the base platform 61 is actuated to begin thetracking portion thereof in contact with a predetermined portion of theinner sidewall surface of the revolving panel. This consistent contactrelationship with the moving sidewall is made by at least one paneltracking means 49 terminally affixed to the inner end of a hollow tube107 which is arcuately movable in a horizontal plane about pivot means109 located on the top of base platform 61; the pivot means havingheight adjustment provisions 110 to effect adaptability to theapparatus. Horizontal pressure means 111 in the form of an air cylinderlocated on the top of base platform 61, has a horizontal plunger 113oriented to make contact with an impact pad 115 integral to the exteriorof tube 107. The plunger thrust imparts, to the lacquer removalapparatus, horizontal movement in the direction of the axis 104 andremoves the panel tracking means 49 from contact with the panel sidewall15, this being the position of the coating removal means 105 during theaforementioned quiescent state wherein panel loading and unloading isaccomplished. Reciprocal movement to bring the tracking means in contactwith the inner surface of the panel sidewall is imparted by horizontalresilient means 117, in the form of a tensioned spring, which has oneend attached to tube 107 at connection 119 in opposition to a point ofaffixture 121 on base platform 61.

With reference to FIGURES 2, 4, 5, 7, and 8, the flushing liquid 27 issupplied to the nozzle 23, from a source not shown, through a flexibleconduit 123, thence through the hollow tube 107 and its connecting hose125. The inner extremity of the tube 107, distal to pivot means 109, isclosed by the jointure 127 with the vertical support post 129.

Tracking means frame 131 has a slotted opening 133 to receive supportpost 129 which is secured therein by set screw 135. A vertical swivelpin 137, on frame 131, mates with tracking head aperture 141 to providepivoted movement to the head 139. A limit pin 175, adjacent the swivelpin, slidably mates with an arcuate slot 173 in the base of the trackinghead 139 to limit the arcuate movement thereof; the arcuate slot 173being in spaced circumferential relationship with aperture 141. Theupstanding portion 143 of the tracking head has a slotted bore 145 toaccommodate placement of nozzle 23. Clamping screw 147, inserted throughvertical bore 149, mates with a tapped hole, not shown, in upstandingportion 143 to secure the nozzle 23. A pair of rollers 151 and 151,having respective axes 152 and 152, are movably mounted on the trackinghead on vertical pins 153 and 153' in a manner for the peripheriesthereof to extend beyond the forward edge 155 of the head. Thus, therollers make two-point mobile contact with a portion of the innersurface 16 of panel sidewall adjacent the open edge 18 thereof.

The stance of this two-point roller contact with the panel sidewall isdirectly related to the center distance B of the axes 152 and 152'. Aspreviously mentioned, it is important for the distance between thenozzle 23 and the inner surface 16 of sidewall 15 to remainsubstantially constant during panel rotation in order to provide a consistant terminal formation of flushing water upon impingement with thesidewall. To maintain this desired distance relationship, the axesspread or center distance B is determined by the diameter of the rollersand the inner curvature of the panel sidewall. For a round panel, as

7 shown in FIGURE 4, the stance of the two-point roller contact is notcritical as the uniform curvature of the panel 11 facilitates a constantnozzle-sidewall distance relationship to effect a consistent waterimpingement pattern on the panel sidewall during the circumferentialprogression thereof. However, with a rectangular shaped panel 43, asillustrated in FIGURE 9, the stance of the two-point contact of thetracking rollers must be such as to maintain substantially the samenozzle-sidewall distance relationship at the arcuate corners 45 as onthe straightaway portions 47 and 47. Such is accomplished by selecting aroller center distance that will correctly track the corners; thetracking rollers having diameters in accordance therewith. Thus, anaccurate cam follower relationship is provided wherein a definiteportion of the inner surface of the panel sidewall, adjacent the openedge thereof, forms a continuous enclosed cam surface which is followedby the rollers of the tracking means in a consistent manner, the rollersbeing held in contact therewith by the horizontal resilient means 117.

The rectangular panel 45, as shown in FIGURE 9, is held substantially attwo corners by panel retainers 93' having contact pads 99' oriented toeffect seated contact with the panel sidewall portions adjacent thecorners of one side 44 thereof. The compression panel retainer 95 ispositioned at substantially the mid-section of the opposite side 44 ofthe panel with the resilient contact pad 1113' making contact therewith.Predetermined pressure is exerted by lever 161 to securely orient andretain the rectangular panel 43 in an undistorted manner within theaccommodation stage 51 on an axis 104 common to both the panel and thestage.

With reference to FIGURES and 6, the top of the base platform 61 has anopening 159 therein at least as large as the central opening 53 in thepanel accommodation stage 51. Suitably fitted into and positionedtherein is an open drainage well 161, as of stainless steel, having adrainage port 163 to facilitate disposal of the liquid flushingeffluent.

As described, placement of the lacquered panel 11 on the panel rests 79is followed by the compressional orientation and retention of the panelby the respective panel retainers 93 and 95. The operational sequence ofthe mechanical combination 48 is automatically governed by controlcenter 167, designated in FIGURE 4. Details of this center are not shownor described as various known systems of control means can be utilizedto initiate a desired sequence of operations. A multiple sequence timingdevice having provisions for automatic reset is preferred for thisoperation. Functioning of the mechanical combination is actuated bycontrol switch 169 which initiates an automated program of relatedoperations. After the panel has been properly positioned on the panelrests 79 and pressure retained by retainers 93 and 95, the severalvertical pressure means 89 are simultaneously activated to retract theirrespective plungers 91. This retracting action permits the expansion ofthe vertically positioned springs 87 to simultaneously lower the forwardportions 77 of the panel rests 79, thus freeing the open edge 18 of thepanel from any obstructions. Activation of drive means 67 providesrotation to the circular panel accommodation stage 51 whereupon theseveral horizontal pressure means 111 are simultaneously activated toretract their respective plungers 113 thus permitting the horizontallyoriented tension springs 117 to pull the panel tracking means 49 towardthe moving panel sidewall; the tracking rollers 1'51 and 151 makingcontact with the inner surface 16 of the sidewall 15 in the regionadjacent the open edge 18 of the panel. A stream of water 27 is thenceinitiated to issue from each nozzle 23 and impinge upon the movinglacquer-covered panel sidewall. The pattern of water impingement thusformed provides a consistent terminal formation of water 37 having atrimming edge 39 that efiiciently flushes away the extraneous lacquercoating from the panel sidewall, and from around the me- 8 tallicbuttons 17 embedded therein, before the inceptio of lacquer filmformation thereon. The relative rotation between the panel sidewall andthe stream of flushing water should have uniformity and a constant rateof speed to provide the desired pattern of water impingement on thepanel sidewall. The speed of rotation is related to the size of thepanel and the perimetric length of the sidewall portion thereof, andshould be of a rate to provide an initial flush of water to the whole ofthe perimetric length of the sidewall before lacquer film formationmaterializes. Additionally, it is important that splashing impingementand uncontrolled deformation of the peripheral trimming edge of water bestrictly avoided. Upon completion of the flushing operation, therefollows in sequence: cessation of the liquid flow, stoppage of the stagerotation, activation of the horizontal pressure means 111 whereupon theplunger 113 extends to move the tracking means 49 away from contact withthe inner surface 16 of the panel sidewall. Subsequent activation of thevertical pressure means 89 extends the plungers 91 thereof to effectmovement for repositioning the several respective panel rests '79against the open edge 18 of the panel to again provide rest positioningfor the panel when the panel retainers are subsequently released. Thus,the automatic cycle of the mechanical lacquer trimming apparatus iscompleted. As mentioned, the subsequent release of the horizontal panelretainers frees the panel to facilitate removal thereof from thetrimming device.

If desired, auxiliary water nozzles can be oriented in a stationarymanner to provide a fluid rinse for the several panel rest forwardportions 77 when in their lower position during the operational cycle.Thus, the panel rests are kept free of lacquer drainage residue.

The lacquer material remaining in the panel is retained in the form of afilm covering the cathodoluminescent screen area where it adheres inconformance to the topography thereof. Upon drying of the lacquer film,a thin layer of aluminum is applied over the whole of the interior ofthe panel, preferably by a vacuum vaporization technique well known tothe art.

The aluminizing procedure is completed by a baking operation wherein thepanel is subjected to a baking heat of approximately 450 degreescentigrade to decompose and volatilize the lacquer film from the screenarea and remove other volatile materials that may be present.

Thus, a coating removal device is provided which expeditiously prepareslacquer coated color cathode ray tube face panels for aluminizingwherein the discrete removal of the extraneous lacquer material from thepanel sidewall promotes the subsequent formation of an unblemished filmof aluminum over the whole of the interior of the screened panel. Thiscoating removal apparatus advantageously utilizes the inner perimeter ofthe panel sidewall as a cam surface intimately contacted by at least onefollower tracking means accommodating a liquid issuing nozzle tomaintain substantially equidistant relationship therebetween andfacilitate the formation of a uniform pattern of liquid flushingimpingement perimetrically therearound. In addition to the superiorquality of the resultant aluminized tube product, the coating removaldevice provides improved efficiency in color cathode ray tubemanufacturing heretofore unachieved.

While there has been shown and described what is at present consideredthe preferred embodiment of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention as defined by the appendedclaims.

What is claimed is:

1. An apparatus for discretely removing extraneous coating material fromthe inner surface of the sidewall portion of an interiorly coatedsubstantially cup-shaped cathode ray tube face panel, having a screenarea and a perimetrical surrounding sidewall portion, said apparatuscomprising:

a base platform;

rotative support mean positioned relative to said platform forsupporting said coated panel in an inverted manner above said platform;

at least one panel tracking means formed to extend above said platformwithin said inverted panel and being oriented therein for predeterminedmovement on a plane substantially parallel with the top of saidplatform, said tracking means being formed to provide mobile camfollower contact with said panel sidewall during relative movementtherebetween;

at least one liquid issuing nozzle positioned on said tracking means ina manner to effect substantially consistent angular orientation andequidistant relationship with said inner surface of said sidewallthroughout the period of said cam follower contact during said panelrotation, said nozzle being formed to provide and direct at least onestream of flushing liquid to impinge said coated sidewall in asubstantially constant pattern of impingement to flush away theextraneous coating material from at least a portion of said innersidewall surface; and

rotative motion means positioned on said base platform relative to saidsupporting means, said motion means being formed to impart predeterminedrotative relative movement to said panel supporting means whereby saidpanel tracking means provides a substantially perimetrical sweepingmotion of said nozzle with reference to said panel sidewall.

2. An apparatus for discretely removing extraneous lacquer material fromthe inner surface of the sidewall portion of an interiorly coatedcathode ray tube face panel having a cathodoluminescent screen area anda perimetrical surrounding sidewall portion, said apparatus comprismg:

a base platform having a top surface with an open drainage well therein;

a circular panel accommodation stage having a central opening thereinlarger than said panel, said stage being horizontally positioned andperipherally supported above said platform in a manner to permitrotation of said stage about a vertical axis, said central opening ofsaid stage being oriented over said drainage well, the periphery of saidstage being formed to receive linear motion transmission to effectrotation thereof;

at least two panel retainers oriented in spaced apart relationship onsaid accommodation stage adjacent the central opening therein to effectcompression retention against the sidewall exterior of said freshlylacquered panel positioned with the open face thereof in a downwardposition within said central opening, said panel having a vertical axiscommon with said vertical axis of said stage to facilitate conjunctiverotation of said panel and said stage;

motion means positioned on said base platform relative to the peripheryof said stage to impart predetermined rotation to said stage;

at least one panel tracking means formed to extend above said platformwithin the confines of said inverted panel and being oriented thereinfor predetermined movement on a plane substantially parallel with thetop of said platform to provide tracking means contact with the innersurface of said panel sidewall in a cam follower relationship during therotation of said stage;

at least one liquid-issuing nozzle positioned on said tracking means ina manner to effect substantially consistent angular orientation andequidistant relationship with said inner surface of said moving sidewallduring said cam-follower contact therewith, said nozzle being orientedto direct at least one stream of flushing liquid to impinge said lacquercoated sidewall, said nozzle being constructed to issue said stream in amanner to provide a substantially con stant pattern of impingementhaving a discretely formed peripheral trimming edge of liquid with thepredetermined vertical apex thereof substantially following the borderof said lacquer coated screen in a perimetrical sweeping motion to flushaway the extraneous lacquer coating from said inner surface of saidpanel sidewall before lacquer filming materializes; and

control means to effect a programmed sequence of stage rotation, paneltracking actuation, and liquid flushing.

3. An apparatus for discretely removing extraneous liquid lacquermaterial from the inner surface of the sidewall portion of an interiorlylacquered cathode ray tube face panel having a cathodoluminescent screenarea and a perimetrical surrounding sidewall portion, said apparatuscomprising:

a base platform having a top surface with an open drainage well therein;

a circular panel accommodation stage having a central opening thereinlarger than said panel, said stage being horizontally positioned andperipherally supported above said platform in a manner to permitrotation of said stage about a vertical axis, said central opening ofsaid stage being oriented over said drainage well, the periphery of saidstage being formed to receive linear motion transmission to effectrotation thereof;

at least two panel retainers oriented in spaced apart relationship onsaid accommodation stage adjacent the central opening therein to effectcompression retention against the sidewall exterior of said freshlylacquered panel positioned with the open face thereof in a downwardposition within said central opening, said panel having a vertical axiscommon with said vertical axis of said stage to facilitate conjunctiverotation of said panel and said stage;

motion means positioned on said base platform relative to the peripheryof said stage to impart predetermined rotation to said stage;

at least one panel tracking means formed to extend above said platformwithin the confines of said inverted panel and being oriented thereinfor predetermined movement on a plane substantially parallel with thetop of said platform to provide tracking means contact with the innersurface of said panel sidewall, said tracking means having a pair oftracking rollers on a swiveled tracking head to accurately track adefinite portion of the inner surface of said sidewall in a consistentcam follower relationship during the rotation of said stage, saidtracking head having limited arcuate movement;

at least one water-issuing nozzle positioned on said tracking head in amanner to effect substantially consistent angular orientation andequidistant relationship with said inner surface of said moving sidewallduring said cam-follower contact therewith, said nozzle being orientedto direct at least one stream of flushing water to impinge said lacquercoated sidewall, said nozzle being constructeds to issue said stream ina manner to provide a substantially constant pattern of impingementhaving a discretely formed peripheral trimming edge of water with thepredetermined vertical apex thereof substantially following the borderof said lacquer coated screen in a perimetrical sweeping motion to flushaway the extraneous liquid lacquer coating from said inner surface ofsaid panel sidewall before lacquer filming materializes; and

control means to effect a programmed sequence of stage rotation, paneltracking actuation, and liquid flushing.

4. An apparatus for discretely removing extraneous liquid lacquermaterial from the inner surface of the sidewall portion of a freshlylacquered cathode ray tube face panel having a cathodoluminescent screenarea and a peria base platform having a top surface with an opendrainage well therein;

a circular panel accommodation stage having a central opening thereinlarger than said panel, said stage being horizontally positioned andperipherally supported above said platform in a manner to permitrotation of said stage about a vertical axis, said central opening ofsaid stage being oriented over said mined rotation to said stage andsaid panel retained thereon;

at least one panel tracking means formed to extend above said platformwithin the confines of said inverted panel being oriented therein forpredetermined movement on a plane substantially parallel with the top ofsaid platform to provide tracking means contact with a definite portionof the inner surface of said panel sidewall adjacent the edge thereof ina camfollower relationship during the rotation of said stage; drainagewell, the periphery of said stage being at least one liquid-issuingnozzle positioned on said formed to receive linear motion transmissionto effect tracking means in a predetermined horizontal plane rotationthereof; in a manner to effect substantially consistent angular aplurality of spaced-apart panel rests oriented on said orientation andequidistant relationship with said base platform and extended to a planethereabove in 15 inner surface of said moving sidewall during said amanner to provide horizontal placement and temcam-follower contacttherewith, said nozzle being porary rest positioning for said panel WhenSaid oriented to direct at least one stream of flushing liqfreshlylacquered panel is placed with the open face uid to impinge said lacquercoated sidewall, said nozthereof in a downward position within saidcentral zle being constructed to issue said stream in a manopening, saidrests being formed to provide r st S pner to provide a substantiallyconstant pattern of im- P the p edge of Said Panel d eff t hOripingementhaving a discretely formed peripheral zontal positioning thereof, saidrests having pivoted trimming edge of liquid ith th predeterminedortiprovisions beneath said accommodation stag to p cal apex thereofsubstantially following the border mit a su q n lowering of thePositions of Said of said lacquer coated screen in a perimetricalsweeprests in a mann r t be W a n from Said Panel ing motion to fiushaway the extraneous lacquer coatd i accordance with predetermined progrmm ing from said inner surface of said panel sidewall actuation of saidapparatus when said panel is posib f lacquer filn'ling t i li d tionallyretained by subsequently applied retention ntrol means to effect aprogrammed sequence of ap means; paratus actuation to provide stagerotation, panel rest at least two panel retainers oriented in spacedapart relowering, panel tracking actuation, liquid flushing, lationshipon aid accommodation stage adjacent the anel tracking deactivation,cessation of stage rotacentral opening therein being formed as saidretenti d panel t iti i tion means to effect compression retentionagainst the sidewall exterior of said freshly lacquered panel ReferencesCited positioned on said panel rests, ugon colnsummlation UNITED STATESPATENTS of said compression retention sai pane rests eing actuated todrop away from said edge to said lower 1886503 11/1932 Shockey, 118318 X2,763,564 9/1956 McKenzie et al. 118-318 X position to free said edge ofall obstructions, said retained panel having a vertical axis common with2880697 4/1959 Blandmg et 118 320 id ti l axi of said stage tofacilitate conjunc- 2,907,688 10/1959 Payne 134 152 X tive rotation ofsaid panel and said stage; motion means positioned on said base platformrelative to the periphery of said stage to impart predeter- CHARLES A.WILLMUTH, Primary Examiner.

R. L. BLEUTGE, Assistant Examiner.

1. AN APPARATUS FOR DISCRETELY REMOVING EXTRANEOUS COATING MATERIAL FROMTHE INNER SURFACE OF THE SIDEWALL PORTION OF AN INTERIORLY COATEDSUBSTANTIALLY CUP-SHAPED CATHODE RAY TUBE FACE PANEL, HAVING A SCREENAREA AND A PERIMETRICAL SURROUNDING SIDEWALL PORTION, SAID APPARATUSCOMPRISING: A BASE PLATFORM; ROTATIVE SUPPORT MEANS POSITIONED RELATIVETO SAID PLATFORM FOR SUPPORTING SAID COATED PANEL IN AN INVERTED MANNERABOVE SAID PLATFORM; AT LEAST ONE PANEL TRACKING MEANS FORMED TO EXTENDABOVE SAID PLATFORM WITHIN SAID INVERTED PANEL AND BEING ORIENTEDTHEREIN FOR PREDETERMINED MOVEMENT ON A PLANE SUBSTANTIALLY PARALLELWITH THE TOP OF SAID PLATFORM, SAID TRACKING MEANS BEING FORMED TOPROVIDE MOBILE CAM FOLLOWER CONTACT WITH SAID PANEL SIDEWALL DURINGRELATIVE MOVEMENT THEREBETWEEN; AT LEAST ONE LIQUID ISSUING NOZZLEPOSITIONED ON SAID TRACKING MEANS IN A MANNER TO EFFECT SUBSTANTIALLYCONSISTENT ANGULAR ORIENTATION AND EQUIDISTANT RELATIONSHIP WITH SAIDINNER SURFACE OF SAID SIDEWALL THROUGHOUT THE PERIOD OF SAID CAMFOLLOWER CONTACT DURING SAID PANEL ROTATION, SAID NOZZLE BEING FORMED TOPROVIDE AND DIRECT AT LEAST ONE STREAM OF FLUSHING LIQUID TO IMPINGESAID COATED SIDEWALL IN A SUBSTANTIALLY CONSTANT PATTERN OF IMPINGEMENTTO FLUSH AWAY THE EXTRANEOUS COATING MATERIAL FROM AT LEAST A PORTION OFSAID INNER SIDEWALL SURFACE; AND ROTATIVE MOTION MEANS POSITIONED ONSAID BASE PLATFORM RELATIVE TO SAID SUPPORTING MEANS, SAID MOTION MEANSBEING FORMED TO IMPART PREDETERMINED ROTATIVE RELATIVE MOVEMENT TO SAIDPANEL SUPPORTING MEANS WHEREBY SAID PANEL TRACKING MEANS PROVIDES ASUBSTANTIALLY PERIMETRICAL SWEEPING MOTION OF SAID NOZZLE WITH REFERENCETO SAID PANEL SIDEWALL.